Film processing rack having overdriven, individually deflecting spools

ABSTRACT

An improved film transport device for transporting film or other strip material therethrough which device includes a rack having a top driven shaft and a plurality of primary overdriven spools thereon. The primary overdriven spools are spring spools and are adapted to deflect individually. Disposed below the primary overdriven spools is a continuously driven friction drive roller. On the lower part of the device is a secondary shaft having a plurality of idle spools thereon. The film supported by the primary and secondary spools defines a side-by-side loop-to-loop arrangement of the film within the device. The spring spools are all overdriven spools and when an increase in film tension is felt within one or more loops, the primary spool or spools supporting the loops deflects toward the friction drive roller and contacts the friction drive roller whereby a peripheral overdriving force is imparted to said deflected spools. This overdriving force imparts an additional rotative force to the deflected spools thereby overcoming the increase in film tension.

United States Patent Bagdasarian [75] Inventor: Alex Bagdasarian, Waltham, Mass.

[73] Assignee: Artisan Industries Inc., Waltham,

Mass.

[22] Filed: June 25, 1971 [21] Appl. No.: 156,878

Related US. Application Data [63] Continuation-impart of Ser. No. 840,127, June 24, 1969, Pat. No. 3,615,061, which is a continuation-in-part of Ser. No. 620,703, March 6, 1967, abandoned.

[52] US. Cl. 242/55.01, 226/118 [51] B65h 17/42 [58] Field of Search 242/5501; 226/118 [56] References Cited UNITED STATES PATENTS 2,584,293 2/1952 Sachs et al..... 242/55.0l 2,865,630 12/1958 Enkelmann.... 242/5501 3,380,678 8/1968 Feasey et 211...... 226/118 X 3,615,061 10/1971 Bagdasarian 242/5501 July 3, 1973 [5 7] ABSTRACT An improved film transport device for transporting film or other strip material therethrough which device includes a rack having a top driven shaft and a plurality of primary overdriven spools thereon. The primary overdriven spools are spring spools and are adapted to deflect individually. Disposed below the primary overdriven spools is a continuously driven friction drive roller. On the lower part of the device is a secondary shaft having a plurality of idle spools thereon. The film supported by the primary and secondary spools defines a side-by-side loop-to-loop arrangement of the film within the device. The spring spools are all overdriven spools and when an increase in film tension is felt within one or more loops, the primary spool or spools supporting the loops deflects toward the friction drive roller and contacts the friction drive roller whereby a peripheral overdriving force is imparted to said de flected spools. This overdriving force imparts an additional rotative force to the deflected spools thereby overcoming the increase in film tension.

7 Claims, 6 Drawing Figures Patented July 3, 1973 lNVENTOR ALEX BAGDASARIAN BY I F ATTORNEYS FILM PROCESSING RACK HAVING OVERDRIVEN, INDIVIDUALLY DEFLECTING SPOOLS CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of Ser. No. 840,127, filed June 24, 1969, now U.S. Pat. No. 3,615,061 which is a continuation-in-part of Ser. No. 620,703, filed Mar. 6, 1967, now abandoned.

BACKGROUND OF THE INVENTION My invention relates to a transport device for processing continuous strip material such as continuous motion picture processing machines or tape processing machines built on the basic principle of transporting film through a series of wet and dry processing tanks with the film transport device being in usually identical banks which are commonly referred to as racks or banks. Whatever the mode of transportation is used, such as bottom friction drive, top friction drive, top tendency drive, sprocket drive or the like, the individual banks are usually of the same design in any machine from beginning to end. In the wet section of any continuous processing machine, the banks are generally identical and in the dry cabinet if they are not identical they may perhaps be a little longer, but essentially of the same design. The larger and faster the processor, the more critical the design criteria required in the film transport device to guard against film breaks due to varying tension between racks and within racks. The film breaks are generally caused by shrinkage or expansion of film, bearing failure, and a loose strand of film not taken up fast enough. However, the primary reason for film breakage is usually the difference in frictional tension in the spools in different racks, caused by the racks being in different solutions, with an attendant lack of film compensation due to a lack of a reasonable fast rate of corrective response between such racks.

With the advent of single 8 mm. films, particulary 8 mm. color film, present 16 mm. and 35 mm. designs are generally inadequate for the running of this very small width film at reasonably fast and economical speeds. New and improved devices must be provided for more rapid and immediate corrective response between racks while maintaining more uniform film tension within each individual rack. This rapid rate of corrective response is necessary in order to process safely the narrow super 8 mm. film at economical high speeds, to control accurately the exposure or processing residence time within a rack and for the use of viscous and spray methods of processing.

Current methods provide for corrective responses to changes in film tension between racks, but the film tension within an individual rack may vary widely with the loops of film increasing and decreasing collectively or individually. One method provides individual drive means for each of the film loops (see U.S. Pat. No. 2,123,445). When the film shortens and the tension increases the spool contacts the drive roller and film is taken from the next loop. Thus, the corrective response is from loop to loop within the rack. This method is disadvantageous in that tension in each loop may vary widely causing hesitation because in this design individual spools are constantly dancing, that is engaging, (positive drive) and disengaging, (no drive) with the drive rollers. When the tension in a loop increases the rack draws its reserve from the preceding rack and that rack will draw reserve from the next preceding rack and so on down the line to the feed section. If, during the drawing of reserve from rack to rack, a loop increases in tension in an intermediate rack, then a shock wave occurs, that is there may be a lapping over of requirements for film reserve from the same rack.

Another method suggested is to have drive rollers or tires extending above the top spools in each rack. The top spools are kept in almost constant engaging contact with the drive roller, (see U.S. Pat. Nos. 2,584,293 and 2,939,700). When film tension builds up or increases in a loop, the top spools are drawn away from the drive roller with the feed rate of film remaining constant. This method uses a positive drive, that is the spools are constantly engaged with the rollers and when the tension increases, the spools are withdrawn. Generally, the size of the rollers used in the racks will get progressively smaller towards the end of the processing machine and the rollers will begin to develop wear patterns after a period of time. In some designs, springs are used to maintain tension. An inherent disadvantage in the use of springs is in the loss of elasticity in the springs after a period of use. Another obvious disadvantage is a lack of full self-compensation which necessitates the graduating of the rubber drive rollers throughout the processor. Generally, in designs of the latter method there is a hesitating effect or lag time in corrective response which limits the processing speed.

Another embodiment employed in the prior art is the employment of spring spools such as disclosed in U.S. Pat. No. 3,380,678 wherein spring spools are employed as idle spools on a fixed shaft. Although this patent is based on a different theory of operation, it did provide some advantages over other prior art devices, but it was found that the film when moving through the loop-toloop arrangement in the rack experienced binding and- /or sticking.

These and other methods are not entirely satisfactory for the processing of the narrow film where high speeds of to 200 feet per minute are desired, or when the spray process or the new viscous method of developing or treating the film is used instead of the total immersion process, since the corrective response to changes in film tension is not fast enough to maintain the constant film tension within a rack necessary for economical processing speeds.

My invention as disclosed in U.S. Ser. No. 840,127, now U.S. Pat. No. 3,615,061, provided for overdriving a plurality of spools referred to as primary spools and when an increase in film tension was felt within a loop of film within the rack, then an additional rotative force would be imparted preferably to the overdriven spools to relieve this increase in film tension. This could be accomplished by relative movement between the spools and the friction drive roller.

SUMMARY OF THE INVENTION the shaft may be idle spools and'one or more of the spools may be pinned, such as at the feed side of the shaft and the output side of the shaft.

Briefly, my invention comprises a rack having a first set of primary spools thereon which spools are adapted to deflect individually to a response in an increase in film tension. The spools are secured to a continuously driven shaft, the inner diameter of the spools being slightly larger than the outer diameter of the shaft on which they are secured to impart the overdrive to said spools. A second set of spools spaced apart from the primary spools in combination with the first set of spools support and guide the film passing through the rack whereby the film defines a loop-to-loop arrangement. A continuously driven shaft is secured to the rack and has a friction drive roller secured thereto, the outer periphery of the drive roller is spaced apart from one set of spools whereby in response to an increase in film tension, the friction drive roller imparts a rotational overdriving force to at least one of the spools of one of the sets of spools to relieve the increase in film tension.

In the method of my invention, film material to be processed is fed to the rack between the first and second sets of spools to provide a plurality of loop-to-loop arrangements for the strip material within the rack. One set of spools is overdriven at substantially constant torque to move the film through the loop-to-loop arrangement and from the rack.

In response to an increase in film tension one or more of the spools deflect in response to said increase in film tension and a rotational overdriving force is imparted to at least one of the spools of one of the sets of spools to relieve the increase in film tension. In the preferred embodiment all of the spools which are overdriven are adapted to deflect individually and are spaced apart from the friction drive roller whereby the rotational overdriving force is imparted to said overdriven deflected spool. In an alternative embodiment one or more of the spools on the shaft overdriving the spring spools may be pinned such as the initial and last spools on the rack to enhance the introduction of the material into the feed side and the removal of the film material from the output side and either in combination with the pinned and spring spools or soley in combination with the spring spools one or more of the spools on the overdriven shaft may be a normally idle spool which would be overdriven but not adapted to deflect individually.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of my invention;

FIG. 2 is a schematic illustration of a plurality of the racks of my invention employed in at least two continuous tanks of a film processing system;

FIG. 3A and 3B are side views of two embodiments of the spring spools which may be employed with my invention;

FIG. 4 is a side view of the gearing arrangement utilized to drive the shaft of FIG. I;

FIG. 5 is an alternative embodiment of my invention employing combinations of pinned spools, overdriven spools, and overdriven individually deflecting spools.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) Referring to FIG. 1, a rack is shown which comprises sides 12 having journaled thereto a shaft 14. Disposed on the shaft are a plurality of primary spools l6.

Referring to FIG. 3A, the shaft is adapted to pass through the center of the spool 16 and the spool is characterized by a convoluted spring 30 therein. Therefore, the spool may deflect individually and independent of movement of the shaft l4. The inner diameter of the spools 16 is slightly larger than the outside diameter of the shaft 14. A friction drive roller 18 is disposed below the primary spools 16 and spaced apart therefrom. The friction drive roller 18 is secured to a shaft 20 which is journaled to the sides 12 of the rack 10. Idle spools 22 are secured to shaft 24 which shaft is secured in a fixed manner to the sides 12 of the rack. Film 25 is supported by the primary and idle spools which film defines a plurality of loop-to-loop arrange ments within the rack.

FIG. 2 shows in schematic form a series of 10 racks in serial relationship in a tank 26 such as a wet tank. The film 25 passing from the tank 26 passes into a second tank 28 such as a dry tank which may contain, for example, eight racks. Of course, the number of tanks through which the film is processed depends upon the type of processing desired, and also, the particular processing conditions, that is, the type of film being developed. For example, color film for movies or microfilm, the width of the film, 8mm, 16mm, 32mm, etc., and the speed at which the film is to be run, will determine the number of racks per tank and the number of loops within the individual racks as well as the residence time of the film within the particular tanks.

Although the embodiments of FIGS. 1 and 2 show an individual rack secured within a tank, it is of course obvious that either one or both of the sides 12 of the rack 10 could be'replaced by the walls of the tank. That is, the shafts 14, 20, and 24 could be secured to or journaled directly to the walls of one or more of the tanks comprising the entire system. Also, if desired, one or more of the shafts may be secured to the walls of the tank and the remaining shafts secured to separate sides such as 12 and then disposed within the tank. For example, the spools 22 employed as idle spools and shaft 24 which in the preferred embodiments does not rotate, could be secured directly to the walls of the tank. The shafts l4 and 20 could then be secured to sides such as 12 which would then be disposed within the tank. Alternatively, the shaft 20 could be secured and journaled to the sides of the tank and the shaft 14 with the spools thereon secured to the tank in a movable manner.

In addition to the overdriven spring spools 16, if desired, the spools 22 may also be overdriven by continuously driving the shaft 24. the shaft 24 may also or additionally be secured to the sides 12 or the walls of the tank in a movable manner such as disclosed in my U.S. patent application, Ser. No. 840,127, filed June 24, 1969, now U.S. Pat. No. 3,615,061, to provide a breather to this particular shaft. The movement of the shaft 24 including the breather effect may be vertical, lateral, and/or oscillatory as is set forth in detail in my prior cited U.S. application. If the shaft 24 is allowed to move either with vertical or oscillatory motion, then a friction drive roller such as 18 may be disposed adjacent the spools 24 whereby when the shaft 24 moves, the continuously driven friction drive roller would impart an additional driving force to the spools with which it engages. Also, if the shaft 24 is driven, one or more of the spools 22 may be pinned or they may all be pinned, a combination of pinned spools and idle spools (overdriven) and/or spring spools may be employed such as 16,.and in any combination thereof within one or more racks in one or more tanks. The shaft 24 may be journaled to the sides 12 and the spools 22 pinned thereto.

In the operation of my invention, film 25 is threaded through or about the primary and idle spools 16 and 22 to define a plurality of loop-to-loop arrangements of film material as shown most clearly in FIG. 1. As shown in FIG. 2, the film passes through successive racks and from one tank to the next until it is passed through the complete system. A drive train such as disclosed in my above-cited U.S. application and not shown in detail here drives the gear 36 which in turn drives primary gear 38. Gear 38 continuously drives shaft 14 on which shaft are secured the spring spools 16. Gear 38 communicates with roller gear 42 through gear 40. Gear 42 is secured to shaft 20 on which shaft is secured the friction drive roller 18. The gearing arrangement is such and as disclosed in my US. application that the peripheral surface of the friction drive roller 18 is continuously driven as is the shaft 14, but such that this other peripheral surface is driven at a faster rate than the outer edge or surface of the overdriven spools 16 under normal operating conditions. Of course, it may be driven at a slower or equal rate and still impart additional momentum to the engaged spool. Further a pacer or feed spool (not shown) is generally used to aid in the transport of the film through the rack.

When an increase in film tension is felt or occurs within one or more of the loops within any particular rack, the loop shortens with respect to the normal dimensions of the loop. Upon the shortening of the loop, the overdriven spring spool 16 deflects downwardly and its outer periphery engages the continuously driven friction drive roller 18. Of course, in some instances, if the increase in tension or the shortening of the loop is only very slight, then the spring spools, such as described in US. Pat. No. 3,380,678, may deflect and return to their normal position without engaging the friction drive roller. FIG. 38 illustrates an alternate spool arrangement to the spring spools of FIG. 3A, wherein the spool 32 includes a central hub surrounded by an annulus of a flexible material 34, such as foam rubber. However, in most circumstances, when the tension does increase it is to such a degree that the spring spools 16 deflect downwardly striking the friction drive roller 18. Upon engagement of the friction drive roller 18 an additional rotative peripheral driving force greater than that which is normally provided by the rotating shaft within the enlarged diameters of the spools 16 is imparted to the deflected spools with the result that more film is drawn into the particular loop to relieve the increase in film tension.

Generally, the correction within the loop may draw on or require a slight amount of film from a previous loop since when the rack is running under normal conditions, each of the loops has within it a certain amount of slack film. If the tension is such that a great deal of the film is required to overcome the binding and tension within the loop, then film may be drawn from each of the previous loops successively until the condition is corrected. Accordingly, with my invention an improved film transport device is provided which is simple to construct and overcomes the difficulties of the prior art.

Referring to FIG. 5 in an alternative embodiment, one or more of the spools may be pinned to the rotating shaft 14. It is shown that feed spool 44 and output spool 46 are pinned to the shaft to aid in the introduction and removal of film into and from the rack. Also if desired, overdriven spools 48 not adapted to deflect individually may be employed in combination with the spring spools and/or in combination with the spring spools and the pinned spools.

Having described my invention, what I new claim is:

1. A transport device for strip material, such as motion picture film, which comprises:

a. a rack;

b. a first set of spools, including means mounting the spools for individual deflection in response to an increase in film tension;

c. means to secure the said first set of spools to the rack;

d. a second set of spools;

e. means to secure the said second set of spools to the rack, whereby the film to be processed is in a loopto-loop arrangement supported by the first and second sets of spools;

f. a shaft secured to the rack and continuously driven during processing of the film;

g. at least one friction drive roller secured to the shaft for rotation therewith, the outer periphery of the drive roller normally being spaced apart from one set of spools;

h. means to drive the friction drive roller on the shaft at a speed faster than the set of spools from which it is spaced apart; and

. means to overdrive the first set of spools to move the film through the rack, whereby in response to an increase in film tension, the drive roller engages in discontinuous driving contact with at least one of the spools of the first or second sets of spools to impart a further rotational overdriving force to said spools, thereby relieving the increase in film tension.

2. A method of transporting strip material which comprises:

a. feeding strip material to be processed to a rack between first and second sets of spools so as to provide a plurality of loop-to-loop arrangements for the strip material within the rack;

b. overdriving at least one set of spools at substantially constant torque to move the film through the loop-to-loop arrangement and from the rack;

c. deflecting individually the overdriven spools in response to an increase in film tension; and

d. contacting a segmental portion of said deflected spools guiding the loop-to-loop film material by rotational overdriving force to impart a further postive overdrive to the spool when an increase in tension in the loop-to-loop arrangement occurs when the film tension in the loop is not maintained in a uniform manner.

3. An improved transport device for strip material, such as motion picture film,-which device comprises in combination:

a. a rack;

b. a first top shaft secured to the rack;

c. a first set of primary spools on'the top shaft, the spools characterized by an inner diameter which is slightly larger than the outer diameter of the top shaft, at least one of the first set of spools including means mounting said at least one spool for individual deflection in response to an increase in film tension;

d. a second bottom shaft secured to the rack and spaced apart from the top shaft;

e. a second set of spools on the bottom shaft, the first and second set of spools supporting and guiding film passing through the rack in a side-by-side loopto 1oop arrangement;

f. a third shaft g. a friction drive roller secured to said third shaft for rotation therewith, said third shaft and friction drive roller adapted to be driven continuously during the film processing operation, the outer periphery of the friction drive roller spaced apart from the first or second set of spools;

h. means to drive the top or bottom shaft during the film processing operation to overdrive either the first or second set of spools, and to provide overdriven spools which move the film through the loop-to-loop arrangement, and from the rack; and

. means for driving the peripheral surface of the friction drive roller at a faster rate than the peripheral surface of the overdriven spools, means positioning the friction drive roller in relation to the overdriven spools, so that on increase in film tension in one or more of the overdriven spools, the overdriven spool in response to said increase in film tension is placed in discontinuous contact with the peripheral surface of the friction drive roller, whereby a rotational overdriving force is imparted to said spool, so as to relieve the increase in film tension.

4. The transport device of claim 3 wherein the first set of spools is overdriven, and wherein the friction drive roller is positioned between the first and second shafts and just below the first set of spools, so as to impart a rotational overdriving force to one of the first set of overdriven spools when the spool moves downwardly on an increase in film tension and into contact with the friction drive roller.

5. The transport device of claim 3 wherein the second set of spools are idler spools.

6. The film transport device of claim 4 wherein the set of spools which are overdriven include a feed spool and an output spool on the shaft, being the initial and last spools, respectively, on the shaft, the spools pinned to the shaft to aid in the introduction and removal of film into and from the rack.

7. The film transport device of claim 3 wherein the means to deflect comprises a convoluted spring within the spool and surrounding the shaft. 

1. A transport device for strip material, such as motion picture film, which comprises: a. a rack; b. a first set of spools, including means mounting the spools for individual deflection in response to an increase in film tension; c. means to secure the said first set of spools to the rack; d. a second set of spools; e. means to secure the said second set of spools to the rack, whereby the film to be processed is in a loop-to-loop arrangement supPorted by the first and second sets of spools; f. a shaft secured to the rack and continuously driven during processing of the film; g. at least one friction drive roller secured to the shaft for rotation therewith, the outer periphery of the drive roller normally being spaced apart from one set of spools; h. means to drive the friction drive roller on the shaft at a speed faster than the set of spools from which it is spaced apart; and i. means to overdrive the first set of spools to move the film through the rack, whereby in response to an increase in film tension, the drive roller engages in discontinuous driving contact with at least one of the spools of the first or second sets of spools to impart a further rotational overdriving force to said spools, thereby relieving the increase in film tension.
 2. A method of transporting strip material which comprises: a. feeding strip material to be processed to a rack between first and second sets of spools so as to provide a plurality of loop-to-loop arrangements for the strip material within the rack; b. overdriving at least one set of spools at substantially constant torque to move the film through the loop-to-loop arrangement and from the rack; c. deflecting individually the overdriven spools in response to an increase in film tension; and d. contacting a segmental portion of said deflected spools guiding the loop-to-loop film material by rotational overdriving force to impart a further positive overdrive to the spool when an increase in tension in the loop-to-loop arrangement occurs when the film tension in the loop is not maintained in a uniform manner.
 3. An improved transport device for strip material, such as motion picture film, which device comprises in combination: a. a rack; b. a first top shaft secured to the rack; c. a first set of primary spools on the top shaft, the spools characterized by an inner diameter which is slightly larger than the outer diameter of the top shaft, at least one of the first set of spools including means mounting said at least one spool for individual deflection in response to an increase in film tension; d. a second bottom shaft secured to the rack and spaced apart from the top shaft; e. a second set of spools on the bottom shaft, the first and second set of spools supporting and guiding film passing through the rack in a side-by-side loop-to-loop arrangement; f. a third shaft g. a friction drive roller secured to said third shaft for rotation therewith, said third shaft and friction drive roller adapted to be driven continuously during the film processing operation, the outer periphery of the friction drive roller spaced apart from the first or second set of spools; h. means to drive the top or bottom shaft during the film processing operation to overdrive either the first or second set of spools, and to provide overdriven spools which move the film through the loop-to-loop arrangement, and from the rack; and i. means for driving the peripheral surface of the friction drive roller at a faster rate than the peripheral surface of the overdriven spools, means positioning the friction drive roller in relation to the overdriven spools, so that on increase in film tension in one or more of the overdriven spools, the overdriven spool in response to said increase in film tension is placed in discontinuous contact with the peripheral surface of the friction drive roller, whereby a rotational overdriving force is imparted to said spool, so as to relieve the increase in film tension.
 4. The transport device of claim 3 wherein the first set of spools is overdriven, and wherein the friction drive roller is positioned between the first and second shafts and just below the first set of spools, so as to impart a rotational overdriving force to one of the first set of overdriven spools when the spool moves downwardly on an increase in film tension and into contact with the friction drive roller.
 5. The transpOrt device of claim 3 wherein the second set of spools are idler spools.
 6. The film transport device of claim 4 wherein the set of spools which are overdriven include a feed spool and an output spool on the shaft, being the initial and last spools, respectively, on the shaft, the spools pinned to the shaft to aid in the introduction and removal of film into and from the rack.
 7. The film transport device of claim 3 wherein the means to deflect comprises a convoluted spring within the spool and surrounding the shaft. 